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Mass Spectrometry Unit

Samples submission: Guidelines for Proteomics sample submission/prep

Protein quantitation: iTRAQ, SILAC, AQUA

Differential expression utilizing isotope labeling
Currently, we perform iTRAQ quantitative proteomics on a collaborative basis. iTRAQ is the current isotope labeling technology used by most scientists interested in isotope-based quantitative MS. It is an open, unbiased ('omic) differential protein expression, amenable to all types of samples (from ALL cell types to tissue, etc.) Parallel processing of up to 8 samples (iTRAQ 8-plex) within a single LCMS experiment can be done. Data dependent acquisition on the QStar or the LTQ-FT mass spectrometer, pre by multidimensional (LC/LC-MS/MS) separations. MASCOT or SEQUEST database searching is used.

We also offer SILAC-labeled analysis: LC MS/MS and data analysis. Cell-culture set-up not offered, user performs labeling in her/his lab. SILAC is an isotope-based quantitation, with much decreased usage by the mass spec community.

• Protocols for protein extraction from cell lysates or tissue
• Protocols for protein precipitation